NPCs composing that spawngroup :

a_putrid_skeleton (50%)

a_sturdy_skeleton (50%)

NPCs spawning around that spawngroup :
(Max range : 100)

befallen_20, range=89 (-141,-107,-12)

befallen_13, range=79 (-71,-124,5)

a_giant_rat (50%)
a_plague_rat (50%)

befallen_7, range=47 (-82,-92,3)

befallen_6, range=65 (-140,-26,4)

befallen_125, range=70 (-77,25,3)